Sensor including an array of sensor elements and circuitry for individually adapting the sensor elements

An infrared sensor comprising:

• an array of photoconductive infrared sensor elements each providing a corresponding one of plural electrical signals indicative of infrared radiation falling thereon;
• a multiplexing circuit having a like plurality of signal input ports each receiving a respective one of said plural electrical signals and sequentially connecting corresponding signals to an output conductor;
• and
• a like plurality of adaptation input cells each conducting an electrical signal from a respective sensor element of said array to a respective one of said input ports of said multiplexer circuit, each adaptation input cell providing a variably-conductive circuit element conducting a bias current flow through the respective sensor element, and an externally-controllable switch which by its position effects a selective variation in the conductivity of said variably-conductive circuit element.

An infrared sensor including an adaptation circuit for extracting an output signal from a variably-conductive infrared sensor element, which infrared sensor element varies in conductivity in response both to changes in temperature and in response to an external infrared electromagnetic radiation stimulus which is to be sensed, said adaptation circuit of said infrared sensor comprising:

• a resistor, a first transistor, and a capacitor mutually connected in parallel between a source of bias current and said sensor element;
• a second transistor connected in series with said sensor element, and with the parallel combination of said resistor, said first transistor and said capacitor between said bias current source and a ground;
• a feedback conductor connecting a voltage drop signal from said resistor to a gate of said first transistor and externally of said adaptation circuit as said output signal;
• a multiposition switch in a first closed position connecting said voltage drop signal from said resistor to said gate of said first transistor.

A photoconductive infrared sensor comprising:

• an array of photoconductive sensor elements each providing a respective output signal in response to infrared light incident thereon;
• a multiplexer circuit having a like plurality of signal input ports;
• a like plurality of adaptation cell circuits connecting individual output signals from respective sensor elements of said plurality of sensor elements to respective ones of said plurality of input ports;
• each adaptation cell circuit of said plurality of adaptation cells including a respective variable feedback loop variation of which varies said output signal from said sensor element, and an externally-controllable multi-position switch varying said feedback loop in dependence upon the position of said switch.